Across the nation, Toxo was swallowing us one by one, tearing families and cities apart, pulling them under and trampling them into bone. The government had no choice except to take grave action. They could order the infected put down or ultimately watch us all die, the U.N.A. drowning in plague.

The solution made me sick. But it was the sole solution. Like amputating a gangrene limb to save the rest of the patient.

The past doesn't want to let go, but the future demands to be born. Only sacrificing what had already been lost would save tomorrow.

Tomorrow opens on a deceptively relaxed summer day-well, as relaxing as a summer day can be in 2063, with the sun ready to burn human skin in minutes-shortly before 18-year-old Garren and 16-year-old Freya are sent 78 years, 7 months, and 11 days into the past. Just after Garren finds the perfect present for his sister's birthday, the world is ravaged by the Toxo virus which is turning billions of people into horrifying, destructive shells of their former selves. In 1986, Garren and Freya are living in Vancouver, BC, under new identities, slowly regaining their memories of the world they escaped.

Just when Garren and Freya start to get comfortable with their new existence, forces of the U.N.A. (United North America) from the future arrive and take Freya hostage. Garren tries to rescue her, but along the way he runs into Isaac, an acquaintance from 2063, who has a horrifying plan in mind to change the present and hopefully alter the devastating future from which they just managed to escape. With the help of a rogue U.N.A. agent and a version of Freya who thinks she's stuck in virtual reality, Garren must hurry to stop Isaac and his followers from destroying sixty percent of the earth's population.

Similar to Yesterday, Martin weaves together 80s cultural references and politics with futuristic technology and elements of environmental and human devastation. Garren and Freya's relationship, finally beginning to cement itself, suddenly becomes much more tenuous when an attempt to wipe Freya's memory goes awry and Garren has to convince her that she really is from the future. Martin manages to increase the stakes greatly, blending this already fragile romance with futuristic dystopian elements; chapters alternate from past to future and slowly allow readers to piece together the entire story of Garren and Freya's past over the course of the novel. Tomorrow offers readers complex characters (are the U.N.A. operatives unreliable, or can they help? Does Isaac truly believe he can help the future by destroying the past?) and a rich sense of place through descriptions of a historic Vancouver.

While Tomorrow is slightly more convoluted than Yesterday due to the amount of time-travel discussed, the quality of writing is no less entertaining. Martin obviously understands intrigue and knows how to construct a story that leaves readers wanting more with each passing chapter. She also manages to cover difficult and nuanced topics of sexuality and race, as well as environmental destruction and international warfare, with a light touch. While it might be easy for so many heavy themes to get out of control within a shorter text, Martin rarely lets her narrative get away from her (some of the time travel details do get confusing). And even with so many interwoven threads, Martin never makes clear distinctions between good and bad, right or wrong, but instead allows readers to wrestle with their own moral and ethical questions throughout the story.

Tomorrow will appeal to teens of many different reading preferences, but most likely those who are already fans of science fiction and dystopian literature. This companion piece to Yesterday is very much worth seeking out.

Highly Recommended.

Rob Bittner is a graduate of the MA in Children's Literature program at The University of British Columbia in Vancouver, BC. He is currently a PhD student in Gender, Sexuality, and Women's Studies at Simon Fraser University.